Intercommunicating telephone and signaling system



C. E. LOM AX Sept. 3, 1935s INTERCOMMUNICATING TELEPHONE AND SIGNALING SYSTEM Filed July 13, 1953 2 Sheets-Sheet l Sept. 3, 1935. c. E. LoMAx I 2,013,354

INTERCOMMUNICATING TELEPHONE AND SIGNALING SYSTEM Filed July l5, 1933 2 Sheets-SheeI 2 GROUP "55A4 KEY,

6,?00? .SEL

KEY

z/A//Ts ssl., Sly/7CH .fm/.ENTOR- l I CLARE/vee E. LOM/1x Patented Sept. 3, 1935 @itali ST'ES Z,tl3,354

PATENT @FFME INTERCOMMUNICATENG TELEPHONE AND SIGNALNG SYSTEM Application July 13, 1933, Serial No. 680,169

12 Claims.

The present invention relates in general to telephone and signal systems and specically to small interccmmunicatlng telephone or signal systems adaptable for use in h-otels, schools, and

other institutions. The principal object of the invention is the provision of a more inexpensive and simpler system which will furnish local communication service in a reliable manner.

According to the system or" the invention, a master station provided, together with a number of extension stations, all oi which are connected together to a common talking line circuit. The extension stations are arranged to call the master station, only, while the master station can call any one or a number of the extension stations,

In previous systems oi the above character it was customary to provide a key at each extension station in order to signal the master station, while the master station was arranged with a separate key for cach ci" the extension telephones in, the system. This required a large number of keys at the master station with the consequent large number of conductors. It is an object of this invention to eliminate the signaling keys at the extension stations and greatly reduce the number required at the master station. n accordance with this object, a particular feature of the invention resides in providing a double key operation at the master station inrorder to select any one or a number of extension stations. One of the keys, termed the group selecting key, is arranged upcn actuation to select a group of extension stations of winch the desired station is one, and another key, termed a units selecting key, connects with the particular extension station of the group selected by the group key.

The invention is not necessarily limited to systems involving telephonie communication but is applicable likewise to signaling systems for hotels, schools, etc., where buzzers, lamps, or bells are only provided, and by means of the keys and circuit arrangement according to the invention any signal at any location or any group of signals may be actuated to impart information to persons, which information may be in the form of a code, if desired.

En the system about to be described a maximtun ci one-hundred extension stations and one master station contemplated. The extension stations may therefore be numbered or arranged on a decimal basis and divided into ten different groups, each with a separate group selecting key at the master station, while only a single group of units selecting keys numbered from 1 to 10 is provided.

A further object of the invention is to provide means for simultaneously signaling a group or" extension stations and in accordance with this 5 object a group ringing key is provided which, upon actuation, will signal an entire group of extension stations at once depending upon which group selecting key is operated.

Other objects and features of the invention in- 10 volving certain circuit arrangements and operations will be readily apparent from the detailed description which, together with the drawings, discloses the invention in its preferred torm together with certain modifications. 15

ln the drawings, Fig. 1 illustrates schematically an intercommunicating system showing the nature and principles oi a preferred embodiment ci the invention; Fig. 2 is a modification of the system shown in Fiff. l wherein a saving in Wiring is eiected; While Fig. 3 illustrates a modication wherein a rotary switch is substituted for the units selecting key shown in Fig. l.

Referring now to Fig. l, the drawings illustrate a small interccmmunicating or private telephone system comprising a master station MS and a number of extension telephone stations Nos. "2G, llt, and 68. Only a few extension telephones have been shown for the purpose of illustration, it being understood that the system to be described comprises a maximum number of onehundred extension telephones. n the layout of an example of the type of system or arrangement in which this system is applicable, it is assumed that the master station MS is located in a building on a particular floor While the extension stations Nos. Q6 and i3 are located on another floor or" the same building and the station No. 2G on still another floor. These extensions are arranged on their particular 'floors with other similar sta- 40 tions with which they form a part of a particular group.

A common talking line circuit il and l2 extends from the master station MS in multiple to all oi the :doors of the building and also in multiple to all of the extension telephones of the group on each particular oor. Extension stations Nos. 43 and i8 and others in the same group are connected to common talking line i3 and it, while station No. 2i] and its associated 50 stations in the group are connected to common talking line l5 and iii.

Associated with the master station MS and suitably mounted in a cabinet in close proximity to the station are a number of -manually operated keys or push buttons. In a hundred-station system these keys will consist of ten group see lecting keys each of which corresponds to and is associated with a particular group of extension stations, for example, a group on each iloor of the building. A group of units selecting keys numbered I to I 0 is connected to conductors I to l0 which are in multiple with and common to all the group selecting keys. An additional key, termed a group ringing key, is multipled to the units selecting keys and to all the group selecting keys over common conductors I` to, l0.

It will be observed that station No. 20 is provided with a buzzer or signal 'II which is connected over signaling conductor I 9 with the contacts 35 of group selecting key 2li. Station No. 48 has its signal I2 connected over conductor I8 with contacts 33 of group selecting key 4i), while extension station No. MS has its signal I3 connected over signaling conductor Il with contact springs 3.4 of group selecting. key to. In the group of stations controlled by group selecting key. 2D, the. signals of all stations Nos. 2| to 29 in'the group are connected tothe contacts of this key. In a similar. manner the remaining contacts ot group selecting key 40 are connected to the signals of. theremaining extension stations of.l this group. From the foregoing, it is seen that each group selecting key, of which there are ten, has a conductorextending to the buzzer of signaling device of the extension telephone in its particular group. The operation of any group selecting key will therefore prepare the circuits for allthesignals of all the extension telephones with which the key is associated.V The operation of any one of the units selecting keys numbered I. to Iwill close a circuit from battery through the particular operated units selecting key, over the multiple connections I to Iildepending upon which units key is operated, and then through the particular contactl springs of the operated group selecting key to the signal ofthe wanted extension station.

Connected in multiple to the common conductors I to I0 is the group ringing key which, upon being actuated, connects the battery through all of its contacts directly onto the common conductors I-to I0-and then through the contact springs ofv any one or a number of group selecting keys which may. be operated,` to the signals of all of an associated group of Yextension stations.

It will -be assumed now, for example, that the master.A station MS desires to call the extension station No. 20. The operator thereupon rst actuates the group selecting key 20 which prepares the signaling circuits of all the telephones in that particular group of which extension telephone No.r 20 is one. 'Ihe group selecting keys are all arranged so that they will remain locked in their operated positions. The operator then operates theY unitsY selecting key No. I0. 'Ihis extends the battery circuit through key No. I0, common conductor I0, contact springs 35A of groupfselecting key VZIJ,y signaling conductor I9, signal ll,` switchhook contacts l, common talking lines` I 6.-. and I2, through the lower winding of relayY 20 to ground. Due to the relatively high resistance of the signal lI, the relay. 20 doesnot operate. 'I'he signal, however, operates and attracts the attention of the person assigned to extension stationNo.. 20.

In case the master station MS desires to signal the,v extension station, No. 43, the group selecting kcyqwouldrst ,beoperated and then theunits selectingkey No. 8 :to closeA the signal circuit from battery, contacts of units selecting key 8, come mon conductor 8, contact 33 of group selecting key El), conductor I8 to the signal l2, In a similar manner the extension station No. @t would be selected in the group 49 and then the units key 6 operated. Units keys I to YIll are of the non-locking type and may be manipulated by the operator at the master station MS in any manner to actuate the signal of the called extension station. In the above manner as described any one of the hundred stations in the system may be similarly signaled by merely actuating the group selecting key to select the particular group of which the desired station is one while any one of the units selecting keys Nos. I to I0 are actuated to directly operate the signal of the desired station. This obviates the necessity of providing separate keys for each extension station in the system, and in the example described of onehundred stations only ten group selecting keys would be required while only one group of units selecting keys is necessary. Any particular group of extension stations may be signaled. bythe group ringing key depending upon which group selecting key is operated. It will also be appreciatedthat any number of group selecting keysmay be operated to operate more than one group of signal devicesy at the associated extension sta. tions.

When any particular extension station responds tothe actuation of his calling signal, for example, that of station No. 26, the receiver i4 is removed from theY switchhook, resulting in vthe disconnection of the signal device li at the switchhook contactsV l. At the same time the switchhook contacts l5 close, thereby extending the circuit of the extension telephone through its transmitter l5, receiver lll, switchhook contacts l5, across the common line conductors I5 and. I8 which extend over common talking con-v thereby notifying the operator at the master Y station MS that the called extension station has responded. It will be understood, of course, that in certain instances the operator. at the master stationmay have his receiver removed from the hookl and listen in before thedesired station answers and in this case the signal G would not operate. In any. case,v however, response at the `master. station closesa loop circuit extending. through the transmitter. 6I, receiver 62, switchhook contacts ,53, thrcuglrthe upper and lowerwindings of Irelay 3 5 to. battery andV ground, respectively.` Relay Sil, upon operating, opens its armature 3! from tsback contact, thereby disconnecting the circuit of signal device 6i). The master station MS may now engage in conversation with the extension station No. 20, talking current being furnished for the extension station through the windings of relay 2B while Vthe master station receives its talking current from relay 3@ and its winding. VThe condensers 22 and 23 in the lines II and I2 separate the two sources of potential.

Itwillbe appreciatedthatv the system of selection pointed outl is extremely flexible, for example, the operator at the master station MS may select any one particular extension station,v any group of extensionstations, or anynumber of;

stations simultaneously in different groups for thepurpose of engaging in a conference calling zcircuit. By the operation of any one or a number' of group selecting keys and also by simultaneously .operating any one or a number of the units selecting keys any` particular desired number ci extension stations may be signaled simultaneously and each one, upon responding to its signal, is automatically connected across the common talking lines il and i2 with the telephone of the master station MS.

In certain instances it may be desirable for two or more extension telephones to be connecte-:l together for communication purposes, and this is accomplished by one of the stations first signaling the master station MS in a manner as has been pointed out and then the master station by means of the group selecting and units selecting keys signal the other extension station with which the iirst static-n desires to be connected.

VAfter both stations have been connected to the common talking line li and i2 the master station MS may retire from the connection, and in order to prevent the signaling device 6&3 of the master station MS from being actuated while the two extension stations are connected to the common talking line i l and i2, a holding key HK is provided. It will be seen that when the master station MS has the receiver et placed on the swltchhook 63 the relay 3Q is a deenergized condition and closes its armature 3l on its back contact. This would ordinarily close a circuit for the signal device Sil through ground on front contact of armature 2l of relay 293 which is now operated, through the armature di and its back Contact of relay lill. In order to prevent the unnecessary operation of the signal device Bt under these conditions, the operator at master station MS momentarily operates the holding key HK which closes a circuit from ground at the key through the winding of relay t@ to battery. Relay 120, upon operating, closes a locking circuit for itself through its front Contact and armature 4I back contact and armature Si, to ground on the front contact of armature l on relay Ztl. Relay lit therefore is held operated under control of relay 26 so that as long as the extension stations remain upon the line the signal t@ will not be operated. However, when the common talking line ll and i2 is cleared relay Z deenergizes and opens the circuit for locking relay [is so that the signal 63 is again placed in circuit under control of relay 2i! so that other stations which may desire to signal the master station MS can do so.

It will be appreciated that in the layout of the system described wherein a different group of telephone extension stations is located on different floors of a building it is necessary to extend ten conductors from each group selecting key to the particular door or location of each group of telephones with which it is associated. This entails the ruiming of one-hundred conductors from the master station throughout the system.

Referring now to the modification shown in Fig. 2 it is contemplated in this instance to provide a layout similar to that disclosed in Fig. l wherein a master station is provided and groups of extension stations are provided on each floor of an institution, all connected together over a common talking circuit E8 and 59. Group selecting keys and units selecting keys are likewise provided, but in order to eiiect a considerable saving in the wiring a single conductor from each of the group selecting keys l to le is extended to an individual relay located on the same floor with its associated group of extension stations. For exainple, group selecting key. No. 'l is directly connested with relay 52, while group selecting key 8 is connected to relay 53. The units selecting keys are connected directly in multiple through the contact springs extending to each of the relays connected to the group selecting keys on each floor. In this matter if the master station MS desires to connect with extension station No. 16, for example, the group selecting key l isactuated at the master station, extending ground to the contacts of the key 1 to relay 52 to battery. Relay upon operating, closes all its armatures on its iront contacts, including contact N o. 55. YThe group selecting keys, being of the locking type, remain operated. The operator then actuates the units selecting key No. 6, thereby closing battery through the contacts of key 6, armature and iront contact 55 of relay 52, through the signaling device 52 to ground at the extension stationvl. The extension station, upon responding to the signal, is connected directly to the common talking conductors E8 and 59, thereby in the manner described in connection with Fig. l actuating the signal St at the master station to indicate his response. rlhe other stations in the system may be called in a similar manner or any group of them may be signaled by manipulation of the group selecting keys of any one or a number of the units selecting keys. In this connection it may also be pointed out that the group ringing key has not been shown in this modification, although it may be connected directly to the conductors connected to the units selecting keys for signaling any desired group of extension stations.

While the invention has been more or less described as being applied in connection with a telephone system, it will be appreciated that in certain institutions, such as small hotels or small factories, telephone communication is not al- Ways desirable or too expensive, but some sort of signaling system is required. Telephones may therefore be dispensed with and only the signaling devices may be employed. The operator at a particular master station may operate the group selecting and units selecting keys to signal any signaling station or signal device or any group of devices to summon a particular' person in close proximity to such devices. By proper manipulation of the units selecting keys in accordance with a prearranged code the signal devices may be operated to respond to this code to convey intellig-ence to any person in proximity thereto.

Fig. 3 discloses a modification of the signaling arrangement shown in Figs. l and 2 in that a units'selecting switch is provided in place of the units selecting keys. This switch may take the form of a circular row of contacts l to lll over which a manually operated wiper may be rotated to select any one of the common conductors l to le to directly operate the signal devices which ,have been previously selected or prepared by the group selecting keys which are connected to the common conductors l to le. By employing a rotary switch for the units selector a simpler device than the group of units selecting keys is provided.

From the foregoing description it will be seen that the invention considerably reduces the amount of apparatus necessary at a master station and greatly simplies the operation of selecting a particular extension, thereby rendering a systern of this type a great deal more eicient and inexpensive than similar systems have been previously.

What is claimed is:

1. In a telephone system, extension telephone stations arranged in groups on a talking line, a master station, group selecting keys, one for each of said groups of extension stations at said m'aster station, units selecting keys at said master station common to said group selecting keys, the actuation of one of said group selecting keys selecting the group of extension stations containingthe station desired by the master station, while the actuation of a certain one of the units selecting keys selects the desired extension station in the group selected by said group selecting key, and means for connecting said selected station and said master station together on said talking line.

2. In a telephone system, extension telephone stations arranged in groups, a call signal at each of said stations, a master station, a common talking circuit connecting said master station and all of said extension stations, group selecting keys at said master station one for each group of extension stations, units selecting keys at said master station, the operation of one of said group selecting keys selecting a group of call signals including the signal of the extension station which the master station desires to establish connection with, while the operation of one of said units selecting keys directly operates the call signal of the particular extension station in the selected group, and means for connecting said selected extension station with said master station over said common talking circuit and disconnecting said call signal from operation.

3. In a telephone system', groups of signal stations, a separategroup selecting key for each of said groups of stations, a units selecting key `common to all of said group keys for signaling the particular station in the group selected by said group key, and a signaling key common to said group and units keys for signaling a. group of stations depending on which group key is operated.

4, In a signaling system, stations arranged in groups, a call signal for each station, a group selecting key for each group of stations for selecting the group of call signals associated With said group key, a units group of keys for operating the particular call signal of the group of call signals selected, and a group signaling key for operating the group of call signals selected by any operated group selecting key.

5. In a telephone system, telephone stations arranged in groups, a call signal for each station, a group selecting key for each group of stations for selecting the same, the call signal from each station of .a group being connected to its associated group selecting key, a units selecting key common to all group selecting keys for operating a particular call signal in the group connected to any group selecting key, and a group signaling key common to all of said group selecting keys for operating all of the call signals in a group depending on which group selecting key is operated. Y Y

6. In a telephone system, telephone stations arranged in groups, a call signal for each station, a group selecting key for each group of stations for selecting the same, the call signal from each station of a group being connected to its associated group selecting key, a units selecting key common to all group selecting keys for operating a particular call signal in the group connected to any group selecting key, a group signaling key common to all of said group selecting keys for operating .all of the call signals in a group depending on which group selecting key is operated, and a common talking circuit for all signaled telephone stations to connect to for communication purposes,

7. In a telephone system, telephone stations arranged in groups, a call signal for each station, a group selecting key for each group of stations for selecting the same, the call signal from each station of a group being connected to its associated group selecting key, a units selecting key common to all group selecting keys for operating a particular call signal in the group connected to any group selecting key, and a group signaling key common to all of said group selecting keys for operating all of the call signals in a Agroup depending on which group selecting key is operated, and means at each telephone station for disconnecting its associated call signal from operation. 8. In a telephone system, extension telephones arranged in groups, each telephone having a signaling device, a master station having a signaling device, a vgroup selecting key at said master station for selecting and preparing the circuit of the signal devices for a group of master stations, a units selecting'group'of keys at said master station for directly operating the particular signal prepared by said group selecting keys, means at the desired extension station in response to actuation of a calling signal for operating the sig'- nal of the master station, and means at said master station for disconnecting its signal' from operation.

9. In a telephone system, extension telephones arranged in groups, a signal at each extension station, a master station having a signal thereat, a group selecting key for preparing the circuit for the signal of a particular group of extension stations, a group of units selecting keys for directly operating the signals selected by the group selecting keys, means at the extension station in response to the actuation of its signal device for automatically operating the signal of the master station, and means at said master station for either automatically or manually disconnectin its signal from operation.

l0. In an intercommunicating telephone system, a group of extension stations each having a signaling device therein, a inaster station connected over a common talking circuit with said extension stations, a signal at said master station, means at any of the extension stations for actuating the signal of the master station When it is desired to .establish a connection therewith over said common talking circuit, a holding key at said master station, means responsive to the actuation of the holding key for disconnecting the master station signal so that any other extension stations may be connected together Without sig-- naling the master station.

11. In an intercommunicating Vtelephone sysftem, extension stations divided into groups, a master station, a common talking circuit extending to all of said extension stations and said master station, signals at each of said stations, a group selecting key for selecting a particular group or extension station signals, a Vstation selecting key for directly operating a particular n extension station signal of the selected group, the' removal of the receiver at the master station and the signaled extension station directly con'- necting said stations to said common talking circuit, a pair ofrelays in said 'talking circuit, one

of said relays feeding talking current to said extension station and the other relay to said master station, and means for separating said sources of talking current from each other.

12. In an intercommunicating telephone system, extension stations divided into groups, a master station, a common talking circuit extending to all of said extension stations and said master station, signals at each of said stations, a group selecting key for selecting a particular group of extension station signals, a station selecting key for directly operating a particular eX- tension station signal of the selected group, the removal of the receiver at the master station and the signaled extension station directly connecting said stations to said common talking circuit, a pair of relays in said talking circuit, one of said. relays feeding talking current to said extension station and the other relay to said master station, means for separating said sources of talking current from each other, means controlled by the relay feeding talking current to the extension station for signaling the master station, and means controlled by the relay feeding talking current to the master station for disconnecting the master station signal.

CLARENCE E. LOMAX. 

